The present invention relates to the insertion of a wire, cable or fiber into a protective jacket, and more particularly to a method and apparatus for automatically inserting a wire or fiber into a protective jacket.
As the use of the internet and other communication networks increases throughout the world, the need to transmit large quantities of information becomes particularly important. Because of its high band-width and compact size, fiber optic cable often is used to transmit a large portion of this information. Fiber optic cable is fragile and easily can suffer from physical damage or excessive bending, both of which may compromise its light transmission qualities. Accordingly, fiber optic cable often is encased in a protective sleeve or jacket. Generally, the fiber optic cable is encased in a protective sleeve when the fiber optic cable is manufactured. However, in certain cases, the fiber is not encased in a protective sleeve at the time of manufacture, and it is necessary to insert the fiber into a protective sleeve at a later time. For example, it may be more convenient to assemble a number of optical components together into a module by fusing 250 micron cable rather than 900 micron cable. At the conclusion of the assembly process, it may be desirable to jacket cables exiting the module with an auxiliary 900 micron protective sleeve.
Traditionally, an optical fiber is inserted manually into the protective sleeve. For example, U.S. Pat. No. 5,745,626 teaches to insert one or more optical fibers 10 through a bore 13 formed in a sleeve 18. However, these manual methods are extremely slow and labor intensive and limit the length of fiber that can be inserted into the sleeve. Also, these manual methods can damage or break the fiber, thereby creating inconsistent yields. Further, these manual methods cannot be used with fibers that have been terminated at both ends.
Several other methods have been used to insert a wire or cable into the protective sleeve. U.S. Pat. No. 4,332,436 teaches to insert an optical fiber within a metal tube by flowing a fluid around the fiber and through the tube, whereby the fiber is entrained within the metal tube by the flow of fluid. However, this method requires a complex device to properly deliver the flow of liquid. U.S. Pat. No. 4,593,442 teaches an apparatus that inserts a flexible cable C into a pipe P. The apparatus includes a head 18 comprising a wedge 36 that separates the pipe P and a guide 20 that guides the cable C into the pipe P. The pipe P is resilient and closes automatically as the head 18 is manually drawn by the handle 16. Because the head 18 is drawn manually, this method is tedious and slow.
Also, U.S. Pat. No. 4,212,097 teaches a tool for inserting an optical fiber into an elastomer tube. As shown in FIG. 2, the optical fiber 11 is inserted into the elastomer tube 14 by longitudinally cutting the tube 14 with cutting means 20, spreading apart the cut edges 22 and 23 with separating/guiding means 24 and inserting the fiber 11 into the tube 14. The cutting means 20 and separating/guiding means 24 are included in an assembly 16 (see FIG. 1). As shown in FIG. 1, a traction controlling device 26 is used to pull the tube 14 through the apparatus. The apparatus of U.S. Pat. No. 4,212,097 is directed towards placing a fiber into a tube which loosely encloses the fiber, and also for producing long runs of fiber inserted in the tube. The apparatus does not lend itself to short runs which require the ability to automate the process of inserting short runs of fiber into short runs of tube.
The present invention provides an apparatus and method for inserting a wire, fiber or cable into a protective sleeve. The protective sleeve is slit by a blade along the length of the sleeve and the fiber is inserted into the slit. In one embodiment, the cable and sleeve are transported through the apparatus along an arcuate guide path formed by a friction wheel.
The invention may be implemented to quickly and efficiently insert a wire or cable of any length into a protective sleeve, thereby increasing both cycle time and output yield.
The present invention can be used to insert into a protective sleeve a fiber that has been terminated at both ends.